Perhaps your integrals were artistically drawn and deserved the thick strokes and extra pages, but I find it easier to write with thinner ballpoint pens.

This reminds me of an old tip[1] about bringing your own thin dry-erase markers to onsite interviews, because you would get more whiteboard space that way.

[1] https://steve-yegge.blogspot.com/2008/03/get-that-job-at-goo...